Manufacture of tanning substances



a water to a solution MAUI-U38 OI TA-h'fmG SUBSTANCES Io Drawing.Application filed October 9.

According to this invention substances hav-' ing good tanning propertiesare produced by eating an aromatic sulphonic acid'together withformaldehyde and a dihydroxydiarylsulphone in acid matic sulphonic acidthere may be used the condensation product thereof with formaldeh de orsulphur chloride. The sparingly solu le sul hone passes into solution inthe course 0 the condensation and the product dissolves in all proortions in water, and in feebly acid solution as good tannin pro rties.The products of the invention yield precipitates with ferric chlorideand can be precipitated from their solutions of common salt.

' e proportions of the components and the duration of the heating maybevaried within wide limits.

The following examples illustrate the invention, the pa being by weightExample 1 100 parts of the sulphonation mixture obtained by heating forseveral hours 520 parts of naphthalene with 560 parts of concentratedsul huric acid at 140160 C. until the mass is so uble in .water, areheatedidgether with 100 parts of a dihydroxydiarylsulphone (for instanceone obtained by heating for 3 hours 540 parts of phenol with'180 partsof fuming sulphuric acid of 60 per cent strength at 170180 C. and thendistilling'ofl' the excess of phenol), 50 parts of water and 45 arts offormaldehyde of 30 per cent strength, for about 1 hour at 105-110 C. issoluble to a clear solution in water;'for tanning, the pkroduct is madefeebly acid by addition of a ali lye and is made up of specific gravityB. e solution has a strong capacity for precifiitating gelatine, analously to the vegeta 1e tanning agents; it yields a strong cipitate withferric chloride and the dissolved product can be salted out by means ofcommon salt.

by means Ewample .9

100 parts of naphthalene-sulphonic acid, made as described in Example 1,10 parts of 1m, Serial No. raises,

solution. Instead of aro-' .made as described with and a; term, November10, mo.

water and parts of formaldehyde of 30 per cent strength are heatedtogether for 1 hour at110-120 C. After addin further 10 parts offormaldehyde, of t strength 20 parts of water and 50 arts of thesu-lphonemade as described in xample 1, ther'whole is heated for 1 hourat 105-110 C. Thegproduct may be further treated as .de-. scribed in"xample 1, and has properties analogous to those of the product of thatexample. 2 f p Ewample 8 100 parts of naphthalene-sulphonic acid inExample 1, are melte and mixed with 40 arts of sulphur chloride. hereare then added 40 parts of water, 30 parts of formaldeh de of 30 percent strength and, parts oft e sul hone made as described in Example 1,and the whole is heated for 1 hour to 105-110 C. The further treatmentand the properties of the product are similar to those described inExample 1'.

Ewaniple 4 100 parts of a sulphonation mixture, obtained b heating 100parts of tetrahydronaphthalzne with 100 parts of concentrated sulphuricacid at 120 C. until the mass is soluble in water, are mixed with water,30 parts of formaldehyde of 30 per cent strength and parts of thesulphone made as described in Example 1, and the mixture is heatedfor'about 1 hour at 110 C.

The further treatment and the properties of the product are as describedin Example 1.

Example 5 65 parts of crude cresol are heated with 65 parts ofconcentrated sulphuric acid for 1 hour at (3.; After cooling anddilution with 13 parts of water the product is condensed with 20 partsof is heated for 1% hours at 105-110 O. The

product ismore sparingly soluble in the cold parts of formaldehyde of 30per cent'strength in the cold. After addition ehyde of 30, per ofthesulphone sop than the product of Example 1, but otherwise shows similarproperties.

1 Example 6 Instead of the sulphone used in Example 1,

Example 7 The operation is analogous -to that described in Example 1,but a sulphone is use which is made in the following manner:

arts of crude cresol, consisting o of ortho-, paraan meta-.cresol, aremixe with 180 parts offuming sulph'uricacid 0 per cent strength and themixture is heated for hour at 110 C. After addition of 324 parts ofhenol, the whole is heated for 3 hours at 1 0190 G. and the excess ofphenol is distilled off in a vacuum.

Example 8 The operation is analogous scribed in Example hone made fromphenol there is used a product to be substituted for thesulphone, whichis obtained as follows: 200 parts of honation m1xture of naphthalene and.sul-

phuric acid for hour at 12 addition of 200 parts of phenol the whole isheated for 3 hours at 170180 C. and the excess of phenol is thendistilled off in a vacuum.

What I claim is 1. A process for the manufacture of tanning substances,consisting in heating in aci solution a dihydroxydiarylsulphone withfort1on the usual chara gelatine.

- In witness my name this 26th parts of phenol and orthoa mixture i tothat de- 1, but instead of the sul-,

the sul- .maldehyde in presence of an aromatic sul- I phonic acid.

. formaldehyde in presence of '2. A process for the manufacture oftanning substances, consistingin heating in aci solution a dihydroxydiarlsulphone with a condensation product of an aromatic ,sulphonic acidwith formaldehyde.

3. A process for the manufacture of tanning substances, consisting inheating in acid solution a dihydroxydiarylsulphone with formaldehyde inpresence of a condensation product of an aromatic sulphonic acid withsulphur chloride.

4. A process for the manufacture of tan-. ning substances, consisting inheating in acid solution a naphthalene sulphonic acid with adihydroxydiarylsulphone obtained from a phenol by its heating withfuming sulphuric acid, and with water and formaldehyde.

' 5. As new articles of manufacture,'tanning substances consisting ofthe condensation product from a dihydroxydiarylsulphone, formaldehydeand an aromatic sulphonic acid, said tanning substances showing insolucteristics of preclp tat on with ferric chloride and Oi;precip1tatmg whereof I have hereunto signed if day of September, 1931.

J OSEF 'SCHKFER.

